AN EXPLORATORY STUDY WAS CONDUCTED ON THE INTERACTION BETWEEN COGNITIVE APTITUDES AND VARIED INSTRUCTIONAL TREATMENTS (TEACHING MATERIALS AND TEACHER METHODS) TO DETERMINE IF LEARNING DIFFICULTIES COULD BE SIGNIFICANTLY MINIMIZED BY ALTERING THE CONTENT OF INSTRUCTIONAL TREATMENTS TO FIT THE COGNITIVE APTITUDE PATTERNS OF INDIVIDUAL LEARNERS. THE AUTHORS SUGGESTED THAT ACHIEVEMENT OF THE STUDENT WOULD BE DIRECTLY RELATED TO THE CONGRUENCE BETWEEN HIS PATTERN OF APTITUDES AND THE "FORM OF CONTENT" OF THE MATERIAL TO BE LEARNED. TO SUBSTANTIATE THIS CONTENTION, A PROGRAM OF HIGHLY SIMPLIFIED STUDIES WAS STRUCTURED AND CONDUCTED. SEVEN SERIES OF STUDIES WERE UNDERTAKEN AMONG DIFFERENT GRADE LEVELS--(1) "FORM OF CONTENT" VARIABLES IN EXISTING TEXTUAL MATERIALS WERE IDENTIFIED, (2) REDUNDANCY AS A "FORM OF CONTENT" VARIABLE WAS EXAMINED, INCLUDING REDUNDANCY LEVELS AND COGNITIVE APTITUDES RELATED TO REDUNDANCY, (3) MATERIALS ON SET THEORY CONCEPTS WERE DEVELOPED AND TAUGHT, EMPHASIZING THE APTITUDE COMBINATIONS OF VERBAL-DEDUCTIVE, VERBAL-INDUCTIVE, FIGURAL-DEDUCTIVE, AND FIGURAL-INDUCTIVE, (4) ACHIEVEMENT OF STUDENTS IN CHEMISTRY WAS RELATED TO SIMILARITIES OF TEACHER AND STUDENT APTITUDE PATTERNS WHEN GENERAL ABILITY WAS HELD CONSTANT, (5) PERFORMANCE ON VERBAL AND FIGURAL CONCEPT ATTAINMENT TASKS, PRESENTED BY EITHER COMPUTER-ASSISTED INSTRUCTION OR BY A HUMAN EXPERIMENTOR, WAS RELATED TO APTITUDE VARIABLES BELIEVED TO BE RELEVANT TO THE TASKS, (6) INTERACTIONS OF APTITUDE AND INSTRUCTION IN VOCABULARY LEARNING WERE STUDIED, AND (7) THE EFFECTS OF SYMBOLIC AND SEMANTIC CONTENT ON THE LEARNING OF MATHEMATICAL OPERATIONS WERE ANALYZED. RESULTS OF THESE STUDIES DEMONSTRATED THE FEASIBILITY OF CONTROLLING APTITUDE-INSTRUCTION INTERACTIONS TO ENHANCE LEARNING IN A VARIETY OF SUBJECT-MATTER AREAS AND AT DIFFERENT AGE AND GRADE LEVELS. RELATED INFORMATION MAY BE FOUND IN ED 010 628. (JH)